George m



" To 'ALL- WnoM-ITMAY eoNoERN: A Y Be it known that I, GEQRG' M. Gum), of Boston, in the county of SuOIk, and: State of Massachusetts,

Gn'oRGn'MeUTLD, 0F BOSTON, lMin-s siioHUSETTS.

letters Pittem No. 78,276,A ma May 2 6, '1868,

IMPROVEMENT .1N SOUNDING-Botnn PQR PIANos.

itin rhthute referrer te in ttm @titers `@attent mit mittig part tritt samt,

hvaftveiinvented an Improvement in Sounding-Boards for Piano-Fortesj and Ido hereby declare that the follows,

ing', tziken in eonneetioniwith the drawings Which accompany and' form part of this specicationt is a description f my invention sucient toV enable those skilled in theort to practise it. v

My invention relates toA the construction of a sounding-board forpiano-fort'es, with reference to the employy'z nent'of thin board, with such provision for rigidifying it as shall .not impairitsvib'rating quality.

As ordinarilylmode;sounding-boards arequite thick; andl have wooden bars o`r ribs running right angularly across, andglued to them, to give the requisitestrength, sind they have been made of two thicknessesl ofl boording, (of the' size of the sounding-board,) glued togefhercrossn'ise ofy the grain of the woods. v

My invention consists in'st'reng'theningja soundingboard by two-series o'f ribs,- orva. main and an auxiliary series, the ribs of the main series, preferably,'runnng di'agonnlly'ncros's the under surfncc of the board, and the-ribs ,of the auxiliary series running aeross'the main ribs, 'thus rigidifying and .strengthening the boord .in Bach direction, and admitting of a.,very-thinboard,' having greet freedom of vibration. l

The drawing represents a. sounding-board embodyingjny improvement.

. A shows the underside of the board. Y .B -is `en end view of it.' 'l

C is a. section onA the line :v :e:

On the under surface ofthe board are 'the main-ribs o1' braces c, each made of wthin strip-of b'oard, which is laid dingonnllyucno'ss the 'surfnee of the' board n, and is xglued thereto. v The'ends of .these 'ribs (excepting at the .large end of the soundingrhoard) project under the edge rail'sd.:A These :ribsl run crosswise 1of the grain of the board a, and erefmedeqdite thin, so risposto? 'vibjatonsiof theihoardg and to keep them andthe board from springing', I cross their outer fsn'rfne'es tritiianxiliyhnd,'prefei'blytllicker wooden ribsoi' hors,

e, which are giued to the surfaces of the "matin -ribs c, nherc'theyerossLand theends'of these-bers may also Aextend under the edge rails d.;

The vspecific arrangement'or form of the ribs c :rnd e may differ from u'hat'is shown in the drawings. They may be wide or narroi'vfinore or'less numerous, and at greater or less distance apart, lthe essentiel feature of my invention consisting broadly in the employment ofauxiliary ribs, crossing itnd confined tothe main ribs.

A-It will be obvious that by this' construction the sounding-hoord may be made very thin and sonorous, the

proper-4 strength 'nnd 'rigidity being secured .by th-double series of bars, and that the soundinghoard will bcthus made capable pfquick vibration. v

I claim, in combination with a sounding-board, and the main supporting-ribs c thereof, the auxiliary ribs c,

crossing end secured to the ribs c, substantially zrsshown :ind described. I

GEORGE M. GILD. 

